How to pause consumers while doing maintenance and only process the exiting consumed message

[khanakia]

I have a use case not sure if others have this issue.

• I want to pause all the subscribers to stop listening for the new queues
• I want the subscribers to process already consumed queues
• Once all the existing consumed queues are finished and the subscriber will not accept any new queues I will stop the server
• Do maintenance and deploy the new binary
• Unpause and let the subscribers listen to the queue again

I do not want to break the current process which is already consumed as my queues take hours to finish so if I stop the server in the middle all the current processes will break too.

[ripienaar]

This will be in the next major release, see #4966